Which one among the following is the basis of difference between the Parliamentary and Presidential system of government ?

The fundamental basis of difference between the Parliamentary and Presidential systems of government lies in the relationship between the legislative and executive branches. In a parliamentary system, there is a 'fusion of powers' where the executive is derived from and remains accountable to the legislature [c4, t1, t3]. The executive (Council of Ministers) is part of the legislature and must maintain its confidence to stay in power [t2, t3]. Conversely, the presidential system is built upon the 'doctrine of separation of powers,' where the executive and legislature are independent organs with separate elections and fixed tenures [c1, t4, t6]. While both systems may feature judicial review and specific methods for electing a head of state, the defining structural distinction is whether the executive is an integral part of the legislature (cooperation/fusion) or strictly separate from it [c1, t6].

Sources

1. [1] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 4: Salient Features of the Constitution > El l Parliamentary form of Government > p. 29
2. [2] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 13: Parliamentary System > FEATURES OF PRESIDENTIAL GOVERNMENT > p. 134
3. [3] https://peacemaker.un.org/sites/default/files/document/files/2022/07/undppoliticalsystemsandtheirimpactongoverningrelations28presidentialparliamentaryandhybridsystems29.pdf
4. [4] https://en.wikipedia.org/wiki/Presidential_system